The present invention relates to a novel indazole derivative represented by the following formula (1): 
in which
n represents 0, 1, 2 or 3,
X represents oxygen, sulfur or nitrogen atom,
R1 and R2 each independently represent hydrogen, amino, hydroxy, lower alkyl or cycloalkyl, or together form cycloalkyl,
R3 represents hydrogen; lower alkyl; phenyl or naphthyl which may be unsubstituted or substituted with one to three substituents selected from the group consisting of hydroxy, halogen, nitro, amide, ester, carboxy, cyano, amidinyl, xe2x80x94Oxe2x80x94R5, xe2x80x94NR6R7, phenyl, alkylsulfanyl, R8xe2x80x94SO2xe2x80x94, lower alkyl, lower alkyl substituted with R9, pyridinyl, piperidinyl, morpholinyl, piperazinyl, thienyl and furyl; aromatic and bicyclic aromatic compounds bearing at least one heteroatom selected from nitrogen, oxygen or sulfur atom; C3-7-cycloalkyl bearing at least one heteroatom selected from nitrogen, oxygen or sulfur atom; piperazinyl, imidazolyl, morpholinyl or piperidinyl which may be unsubstituted or substituted with one or two substituents selected from the group consisting of lower alkyl, phenyl, phenyl substituted with halogen, phenyl substituted with alkoxy, phenyl substituted with alkylcarbonyl, biphenyl and naphthyl; thiazole which may be unsubstituted or substituted with amino, mono- or di-lower alkylamino, alkylcarbonylamino, benzylamino, benzyloxycarbonylamino, benzyloxybenzylamino or alkoxycarbonylamino; benzodioxol; isoquinoline; indolyl; or benzimidazole wherein R5 represents phenyl, benzyl, lower alkyl, alkoxyalkyl, alkoxyalkoxylalkyl, alkoxyalkoxyalkoxyalkyl, aminoalkyl or mono- or di-alkylaminoalkyl, R6 and R7 are identifical or different from each other and represent hydrogen, lower alkyl, oxygen or benzyl, or joined to form a ring, and R8 and R9 represent each independently lower alkyl, amino, morpholinyl, piperazinyl, N-alkylpiperazinyl or imidazole, and
R4 represents nothing when X is oxygen or sulfur atom, but represents hydroxy or alkoxy when X is nitrogen atom,
pharmaceutically acceptable salt, solvated product and isomer thereof which are useful as inhibitors for Cyclin Dependent Kinase(hereinafter, refered to as xe2x80x9cCDKxe2x80x9d), and method for preparing the same.
The present invention also relates to an agent for inhibiting and treating diseases involving cell proliferation such as cancer, inflammation, restenosis and angiogenesis which comprises the compound of formula (1) as an active ingredient together with a pharmaceutical carrier.
Researches on cell division process in molecular level have been extensively performed from the late 1980""s through study of division of frog oocytes, analysis several yeast cell growth or characterization of induced mutants by radiation and study of the tumor suppressor Rb. In the 1990""s, it is discovered that small molecular cell growth regulator controls cell division process(i.e. growth, differentiation, cytogenesis, aging and apoptosis etc.) through its own regulatory function. These results were very useful for more precise understanding of the pathology of several diseases.
A representative example is cancer. In transformation process from normal cells to cancer cells, it was frequently observed that cell growth regulator loses its own function. That is to say, in cancer cells, the cell growth regulator shows an abnormal activity, which is deeply associated with invasion/metastasis which is crucial in the cancerpathology. Particularly, cell cycle deregulation is recognized to be a direct cause of cancer since cancer occurs in experimental animal when overexpression or knock-out of cell growth regulator is induced by using tranformed animal.
The cell growth is under positive or negative regulation in the same manner as other biological regulations. The major pathway of cell cycle regulation known up to now is based on CDK activity and, as a result of studies on many cancer cells and carcinogenesis mechanisms, it was confirmed that problems of positive or negative regulation on CDK activity result in carcinogenesis in many cases. That is, cancer may occur when positive or negative regulation and timely regulation which is important for cell growth regulation are disrupted.
The representative CDKs of mammals are CDK4(Cyclin dependent kinase 4) and CDK2 which show their activity in G1-S phase of cell cycle, CDC2(CDK1) which shows its activity in G2-M phase, and so on. It is known that CDK4 and CDK2 activities are regulated by check point of G1-S cell cycle and CDC2 activity by check point of G2-M. In many cancer cells, abnormalities appear in the regulatory mechanism of CDK4, CDK2 and CDC2(CDK1) and in fact, it was confirmed that induced abnormalities cause cancer in the transformed animal. Therefore, CDK4, CDK2 and CDC2(CDK1) among several kinds of CDKs are suitable as a target of anti-cancer agents.
The results of studies on relation between these CDKs and carcinogenesis will be explained in more detail in the following,
The relation between the abnormal regulation of CDK4 activity and carcinogenesis is observed in several cancer tissues. The deletion of p16 and p15 genes generating proteins which inhibit CDK4 activity and the overexpression of cyclin D1 indispensable for CDK4 activity are observed in several kinds of cancer, which suggests that malignant phenotype may be expressed when CDK4 activity is deregulated. Furthermore, it was reported that p16 knocked-out mouse has such a high carcinogenesis rate as p53 knocked-out mouse, which suggests that malfunction of p16 on CDK4 regulation is a cause of carcinogenesis. From these experimental results, deregulation of CDK4 activity may be a cause of carcinogenesis and play a role in maintenance of phenotype of cancer cell. Therefore, CDK4 inhibitors may have anti-cancer effects.
It was reported that overexpression of cyclin E indispensible for CDK2 activity is observed in some breast cancers, deeply associated with metastasis of breast cancer, inhibits cell apoptosis under low serum condition and induces anchorage independent growth, and that hyperproliferation and neoplasia of mammary epithelial cells are observed in transformed animal with overexpressed CDK2 by MMTV promoter, which suggests that CDK2 activity is related with the progress or maintenance of cell transformation and CDK2 inhibitors may also have anti-cancer effects.
Furthermore, it is discovered that CDC2(CDK1), CDK3, CDK5, CDK6 and CDK7 play an important role in each phase of cell division. These are classified into CDKs family. In addition to cyclin D1 and E, cyclin A, B, C, D2, D3, D4, F and G are also calssified into the same family.
On the basis of the above-mentioned research, efficient inhibitors of these CDKs may be useful as anti-cancer agents. Therefore, recently, these inhibitors have been developed.
As effective CDK inhibitors developed hitherto, there exists Flavopiridol, compound of the formula (A): 
[Ref.: EP 0,241,003(1987) and 0,336,061(1990)].
In addition, a purine derivative of the formula (B): 
has been recently developed[Ref: WO 97/20842].
Recently, a CDKs inhibitor having aminopyridine structure of the formula (C): 
is disclosed in WO 98/33798.
However, the CDK inhibitors developed up to now could not have satisfactory effects.
So, the present inventors have made widespread and concentrative researches on CDK inhibitors, particularly indazole-based compounds, and as a result, found that a component of the formula (1) which has a quite different structure from any other known CDK inhibitors inhibits CDKs enzymes effectively and finally, completed the present invention.
The object of the present invention is to provide a novel indazole derivative of formula (1), a process for preparing the same, and a composition for inhibiting and treating diseases involving cell proliferation such as cancer, inflammation, restenosis and angiogenesis which comprises as an active ingredient the compound of formula (1). In this specification, CDKs include all of CDK2, CDK4, CDC2(CDK1), CDK3, CDK5, CDK6, CDK7 etc., and cyclin includes cyclin D1, E, A, B, C, D2, D3, D4, F and G
Hereinafter, the present invention is explained in detail.
The present invention relates to a novel indazole derivative represented by the following formula (1): 
in which
n represents 0, 1, 2 or 3,
X represents oxygen, sulfur or nitrogen atom,
R1 and R2 each independently represent hydrogen, amino, hydroxy, lower alkyl or cycloalkyl, or together form cycloalkyl,
R3 represents hydrogen; lower alkyl; phenyl or naphthyl which may be unsubstituted or substituted with one to three substituents selected from the group consisting of hydroxy, halogen, nitro, amide, ester, carboxy, cyano, amidinyl, xe2x80x94Oxe2x80x94R5, xe2x80x94N R6 R7, phenyl, alkylsulfanyl, R8xe2x80x94SO2xe2x80x94, lower alkyl, lower alkyl substituted with R9, pyridinyl, piperidinyl, morpholinyl, piperazinyl, thienyl and furyl; aromatic and bicyclic aromatic compounds bearing at least one heteroatom selected from nitrogen, oxygen or sulfur atom; C3-7-cycloalkyl bearing at least one heteroatom selected from nitrogen, oxygen or sulfur atom; piperazinyl, imidazolyl, morpholinyl or piperadinyl which may be unsubstituted or substituted with one or two substituents selected from the group consisting of lower alkyl, phenyl, phenyl substituted with halogen, phenyl substituted with alkoxy, phenyl substituted with alkylcarbonyl, biphenyl and naphthyl; thiazole which may be unsubstituted or substituted with amino, mono- or di-lower alkylamino, alkylcarbonylamino, benzylamino, benzyloxycarbonylamino, benzyloxybenzylamino or alkoxycarbonylamino; benzodioxol; isoquinoline; indolyl; or benzimidazole wherein R5 represents phenyl, benzyl, lower alkyl, alkoxyalkyl, alkoxyalkoxylalkyl, alkoxyalkoxyalkoxyalkyl, aminoalkyl or mono- or di-alkylaminoalkyl, R6 and R7 are identifical or different from each other and represent hydrogen, lower alkyl, oxygen or benzyl, or joined to form a ring, and R8 and R9 represent each independently lower alkyl, amino, morpholinyl, piperazinyl, N-alkylpiperazinyl or imidazole, and
R4 represents nothing when X is oxygen or sulfur atom, but represents hydroxy or alkoxy when X is nitrogen atom,
pharmaceutically acceptable salt, solvated product and isomer thereof which have efficacies on inhibiting and treating diseases involving cell proliferation such as cancer, inflammation, restenosis and angiogenesis through a mechanism of inhibiting CDKs activity.
Among the indazole derivatives of formula (1) according to the present invention, the preferred compounds include those wherein
n represents 1 or 2,
X represents oxygen, sulfur or nitrogen atom,
R1 and R2 each independently represent hydrogen, amino, hydroxy, lower alkyl or cycloalkyl, or together form cycloalkyl,
R3 represents hydrogen; lower alkyl; phenyl which may be unsubstituted or substituted with one to three substituents selected from the group consisting of hydroxy, halogen, nitro, amide, cyano, amidinyl, xe2x80x94Oxe2x80x94R5, xe2x80x94N R6 R7, phenyl, lower alkylsulfanyl, R8xe2x80x94SO2xe2x80x94, lower alkyl, lower alkyl substituted with R9, pyridiny, piperidinyl, morpholinyl, thienyl and furyl; naphthyl; piperazinyl or imidazolyl which may be unsubstituted or substituted with one or two substituents selected from the group consisting of lower alkyl, phenyl, phenyl substituted with halogen, phenyl substituted with lower alkoxy, phenyl substituted with acetyl, biphenyl and naphthyl; morpholinyl; piperidinyl; thiazole which may be unsubstituted or substituted with amino, mono- or di-lower alkylamino, acetylamino, benzylamino, benzyloxyamino, benzyloxybenzylamino or lower alkoxycarbonylamino; benzodioxol; 3,4-dihydroisoquinoline; or benzimidazole wherein R5 represents phenyl, benzyl, lower alkyl, lower alkoxyalkyl, polyethyleneglycolyl, aminoalkyl or mono- or di-lower alkylaminoalkyl, R6 and R7 are identifical or different from each other and represent hydrogen, lower alkyl, oxygen or benzyl, or joined to form a ring, and R8 and R9 each independently represent lower alkyl, amino, morpholinyl, piperazinyl, N-alkylpiperazinyl or imidazole, and
R4 represents nothing when X is oxygen or sulfur atom, but represents hydroxy or alkoxy when X is nitrogen atom.
The term xe2x80x9clower alkylxe2x80x9d in the substituents of the compound of formula (1) refers to a linear or branched saturated radical of from 1 to 6 C atoms such as methyl, ethyl, isopropyl, isobutyl and t-butyl. The term xe2x80x9clower alkoxyxe2x80x9d refers to a linear or branched radical of from 1 to 6 C atoms such as methoxy, ethoxy, isopropoxy, isobutoxy and t-butoxy.
Since the compounds of formula (1) according to the present invention may have asymmetric carbon centers, they can be present in the form of enantiomer or diastereomer, and mixtures thereof including racemate.
Therefore, the present invention also includes all these isomers and their mixtures.
The compound of formula (1) according to the present invention may also form a pharmaceutically acceptable salt. Such a salt includes non-toxic acid addition salt containing pharmaceutical acceptable anion, for example a salt with inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, hydrobromic acid, hydroiodic acid, etc., a salt with organic carboxylic acids such as tartaric acid, formic acid, citric acid, acetic acid, trichloroacetic acid, trifluoroacetic acid, capric acid, isobutanoic acid, oxalic acid, malonic acid, succinic acid, phthalic acid, gluconic acid, benzoic acid, lactic acid, fumaric acid, maleic acid, etc., or a salt with sulfonic acids such as methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, naphthalenesulfonic acid, etc.
The representative examples of the compound of formula (1) according to the present invention are
1. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-phenylacetamide,
2. 2-(3-chlorophenyl)-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]acetamide,
3. 2-[4-(benzyloxy)phenyl]-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]acetamide,
4. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-(4-hydroxyphenyl)acetamide,
5. 2-[4-(dibenzylamino)phenyl]-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]acetamide,
6. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-[4-(methylamino)phenyl]acetamide,
7. 2-(4-aminophenyl)-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]acetamide,
8. 2-(4-chlorophenyl)-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]acetamide,
9. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-(4-fluorophenyl)acetamide,
10. 2-[1,1xe2x80x2-biphenyl]-4-yl-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]acetamide,
11. 2-(3-bromophenyl)-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]acetamide,
12. 2-(4-bromophenyl)-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]acetamide,
13. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-phenylethanethioamide,
14. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-Nxe2x80x2-hydroxy-2-phenylethaneimidoamide,
15. 2-(1,3-benzodioxol-5-yl)-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazole-3-yl]acetamide,
16. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-(1-naphthyl)acetamide,
17. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-(2-naphthyl)acetamide,
18. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-(3-nitrophenyl)acetamide,
19. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]acetamide,
20. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-[4-(methylsulfanil)phenyl]acetamide,
21. 2-(3-aminophenyl)-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]acetamide,
22. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]ethanethioamide,
23. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-Nxe2x80x2-hydroxyethaneimidoamide,
24. 2-(3,4-dichlorophenyl)-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]acetamide,
25. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-3-phenylpropanamide,
26. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-(4-isopropylphenyl)acetamide,
27. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-(3-methylphenyl)acetamide,
28. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-(4-methylphenyl)acetamide,
29. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-[4-(methylsulfonyl)phenyl]acetamide,
30. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-(4-methyl-1-piperazinyl)acetamide,
31. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-(4-morpholinyl)acetamide,
32. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-(1-piperidinyl)acetamide,
33. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-[4-(4-pyridinyl)phenyl]acetamide,
34. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-[4-(1-piperidinyl)phenyl]acetamide,
35. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-[4-(1-morpholinyl)phenyl]acetamide,
36. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-[4-(3-thienyl)phenyl]acetamide,
37. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-[4-(4-morpholinylsulfonyl)phenyl]acetamide,
38. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-(4-methoxyphenyl)acetamide,
39. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-[4-(2-furyl)phenyl]acetamide,
40. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-4-[(4-methyl-1-piperazinyl)sulfonyl]phenylacetamide,
41. 2-(1H-benzimidazol-1-yl)-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]acetamide,
42. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-(4-ethoxyphenyl)acetamide,
43. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-[4-(4-morpholinylmethyl)phenyl]acetamide,
44. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-4-[(4-methyl-1- piperazinyl)methyl]phenylacetamide,
45. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-(4-nitrophenyl)acetamide,
46. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-[4-(1H-imidazole-1-ylmethyl)phenyl]acetamide,
47. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-(4-phenyl-1H-imidazol-1-yl)acetamide,
48. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-(4-phenyl-1-piperazinyl) acetamide,
49. 2-[3,4-dihydro-2(1H)-isoquinolinyl]-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]acetamide,
50. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-[4-(4-chlorophenyl)-1-piperazinyl]acetamide,
51. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-[4-(4-methoxyphenyl)-1-piperazinyl]acetamide,
52. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-[4-(2-ethoxyphenyl)-1-piperazinyl]acetamide,
53. 2-[4-(4-acetylphenyl)-1-piperazinyl]-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]acetamide,
54. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-(4-phenoxyphenyl)acetamide,
55. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-1-phenylcyclopentanecarboxamide,
56. 2-cyclopentyl-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-phenylacetamide,
57. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-phenylbutanamide,
58. t-butyl 4-(2-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]amino-2-oxoethyl)-1,3-thiazol-2-ylcarbamate,
59. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-4-[2-(2-ethoxyethoxy)ethoxy]phenylacetamide,
60. 2-(2-amino-1,3-thiazol-4-yl)-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]acetamide,
61. 2-[4-(4-bromophenyl)-1H-imidazol-1-yl]-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]acetamide,
62. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-[4-(2-naphthyl)-1H-imidazol-1-yl]acetamide,
63. 2-(4-[1,1xe2x80x2-biphenyl]-4-yl-1H-imidazol-1-yl)-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]acetamide,
64. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-[2-(ethylamino)-1,3-thiazol-4-yl]acetamide,
65. 2-[2-(diethylamino)-1,3-thiazol-4-yl]-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]acetamide,
66. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-(4-2-[2-(2-methoxyethoxy)ethoxy]ethoxyphenyl)acetamide,
67. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-(4-ethoxy-3-nitrophenyl)acetamide,
68. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-(2-methylphenyl)acetamide,
69. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-[3-(ethylamino)phenyl]acetamide,
70. 2-[3-(diethylamino)phenyl]-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]acetamide,
71. 2-(3,5-dimethoxyphenyl)-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]acetamide,
72. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-[4-(ethylamino)phenyl]acetamide,
73. 2-[4-(diethylamino)phenyl]-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]acetamide,
74. 2-(3-chloro-4-ethoxyphenyl)-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]acetamide,
75. 2-[4-(2-aminoethoxy)phenyl]-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]acetamide,
76. 2-[2-(acetylamino)-1,3-thiazol-4-yl]-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl-1H-indazol-3-yl]acetamide,
77. 2-(2-[4-(benzyloxy)benzyl]amino-1,3-thiazol-4-yl)-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]acetamide,
78. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-(3-ethoxyphenyl)acetamide,
79. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-[4-ethoxy-3-(4-morpholinylsulfonyl)phenyl]acetamide,
80. 2-[3-(aminosulfonyl)-4-ethoxyphenyl]-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]acetamide,
81. N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]-2-4-ethoxy-3-[(4-methyl-1-piperazinyl)sulfonyl]phenylacetamide, and
82. 2-[4-(2-aminoethoxy)phenyl]-N-[5-(1,1-dioxo-1xcex6-isothiazolidin-2-yl)-1H-indazol-3-yl]acetamide.
The processes for preparing the compound of formula (1) as defined above are depicted in the following Scheme (1): 
wherein R1, R2, R3 and n are as previously described, and Boc represents t-butoxycarbonyl.
That is, as depicted in the above Scheme (1), an amidoxime of the following formula (2): 
is prepared by reacting anthranilonitrile with hydroxylamine, and the amidoxime thus prepared is then reacted with ester to produce a 3-aminoindazole of the following formula (3): 
wherein R1, R2 and R3 are as previously described.
A 1-position of 3-aminoindazole is protected by t-butylcarbamate to produce a compound of the following formula (4): 
wherein R1, R2, R3 and n are as previously described, and Boc represents t-butoxycarbonyl, and then nitro group at 5-C is reduced to produce an amine of the following formula (5): 
wherein R1, R2, R3 and n are as previously described, and Boc represents t-butoxycarbonyl.
A sulfonamide of the following formula (6): 
wherein R1, R2, R3 and n are as previously described, and Boc represents t-butoxycarbonyl, which is obtained by reacting the compound of formula (5) with sulfonyl chloride is cyclized through intramolecular ring-closure to synthesize a dioxoisothiazolidine of the following formula (7): 
wherein R1, R2, R3 and n are as previously described, and Boc represents t-butoxycarbonyl.
Finally, the compound of formula (7) is deprotected to give the compound of formula (1). A compound of formula (1) wherein X is oxygen atom is reacted with Lawesson""s reagent (2,4-bis-(4-methoxyphenyl-1,3-dithia-2,4-diphosphethane-2,4-disulfide) to produce a compound of formula (1) wherein X is sulfur atom, or the compound of formula (1) wherein X is sulfur atom is reacted with a compound of the following formula (8):
R4xe2x80x94NH2xe2x80x83xe2x80x83(8)
wherein R4 is as previously described, to produce a compound of formula (1) wherein X is nitrogen atom:
The indazole derivative of formula (1) according to the present invention may also be synthesized through amidization followed by deprotection of an indazole intermediate of the following formula (9): 
wherein Cbz represents benzyloxycarbonyl.
Specifically, the indazole intermediate of formula (9) is reacted with an acyl halide of the following formula (10): 
wherein R1, R2, R3 and n are as previously described in the formula (1), and Xxe2x80x2 represents halogen, for example, Cl, or Br., and then subjected to deprotection to give the compound of formula (1), which will be described in the following Example 2.
Meanwhile, the indazole derivative of formula (9) is prepared by using anthranilonitrile as a starting material, as depicted in the following Scheme (2): 
wherein R1, R2, R3 and n are as previously described, Boc represents t-butoxycarbonyl, and Cbz represents benzyloxycarbonyl.
Specifically, as depicted in the Scheme (2) above, the indazole derivative of formula (9) is prepared by reacting amidoxime of anthralilonitrile with ethyl phenylacetate in accordance with the above Scheme (1) to produce an indazole derivative of the following formula (11): 
which corresponds to the compound of formula (1), protecting a nitrogen at 1-position of the indazole derivative by benzylcarbamate to produce a compound of the following formula (12): 
wherein Cbz represents benzyloxycarbonyl, cleaving an amide bond in the compound of formula (12) using di-t-butylcarbonate to produce a compound of the following formula (13): 
wherein Boc represents t-butoxycarbonyl, and Cbz represents benzyloxycarbonyl, and removing t-butoxycarbonyl groups.
However, the process for preparing the compounds according to the present invention has been described in detail for the purpose of illustration, but should not be interpreted to limit the invention. The compounds of the present invention can easily be prepared by conventional methods of organic synthesis described in the prior art or combinations thereof, and such combinations are well known to those skilled in the art.
The compound of the formula (1) according to the present invention has an inhibitory activity against CDK, and thus may be put to a good use as an agent for inhibiting and treating diseases involving cell proliferation such as cancer, inflammation, restenosis and angiogenesis. Accordingly, another object of the present invention is to provide a composition for inhibiting and treating diseases involving cell proliferation such as cancer, inflammation, restenosis and angiogenesis which comprises the compound of formula (1), pharmaceutically acceptable salt, solvated product or isomer thereof as an active ingredient together with a pharmaceutically acceptable carrier.
When the compound of the present invention is administered for clinical purpose, it is preferably administered in an amount ranging from 1.0 to 50 mg/kg of body weight a day. The total daily dosage may be administered in one time or over several times. However, the specific dosage for a specific patient can be varied according to the specific compound used, body weight of the subject patient, sex, hygienic condition, diet, time or method of administration, excretion rate, mixing ratio of the medicine, severity of the disease to be treated, etc.
The compound of the present invention may be administered in the form of injections or oral preparations.
Injections such as sterilized aqueous or oily suspension for injection may be prepared by using suitable dispersing agent, sufactant or suspension agent according to the known method. As solvents to be used for preparing injections, water, Ringer""s fluid and isotonic NaCl solution can be mentioned, and sterilized fixing oil is also used as the solvent or suspension medium. Any non-stimulative fixing oil including mono- or di-glyceride can be used for this purpose, and also fatty acid such as oleic acid can be used for injection formulation.
As the solid preparation for oral administration, capsules, tablets, pills, powders and granules, preferably capsules and tablets can be mentioned. It is desirable for tablets and pills to be formulated into enteric-coated preparation. Solid preparations may be prepared by mixing the active compound of formula (1) according to the present invention with at least one carrier selected from the group consisting of inert diluents(e.g. sucrose, lactose, starch, etc.), lubricants(e.g. magnesium stearate), disintegrants, and binders.
When it is intended to produce the desired anti-cancer effects by administering clinically the compound of the invention, the active compound of the formula (1) can be administered together with at least one agent selected from the known anti-cancer agents. In this manner, as anti-cancer agents to be administered with the compound of the invention, 5-fluorouracil, cisplatin, doxorubicin, taxol, gemcitabine, etc. can be mentioned.
However, the preparations containing the compound according to the invention intended for anti-cancer effect are not limited to those described above, and any preparations useful for treating and inhibiting cancers can be included.
The present invention is more specifically explained by way of the following prepartions and examples. However, it should be understood that the present invention is not limited to these examples in any manner.
1-1) Synthesis of 2-Amino-N-hydroxy-5-nitrobenzenecarboxyimidoamide
27.8 g (400 mmol) of hydroxylamine hydrochloride and 33.6 g (400 mmol) of sodium bicarbonate were dissolved in 140 ml of water, and then a solution of 33.6 g (200 mmol) of anthranilonitrile in 520 ml of ethanol was added thereto. The mixture was heated under reflux for 12 hours, and then cooled to room temperature. The resulting precipitate was filtered and washed with water and diethyl ether to give 37.2 g of the title compound in a yield of 95%.
1H NMR (DMSO-d6, ppm): xcex4 6.02 (2H, s), 7.78 (1H, d), 7.80 (2H, s), 7.92 (1H, dd), 8.35 (1H, d), 9.98 (1H, s); FAB MS(m/e)=197[M+1].
1-2) Synthesis of N-(5-Nitro-1H-indazol-3-yl)-2-phenylacetamide
29.4 g (150 mmol) of the compound obtained in Preparation 1-1) was dissolved in 500 ml of tetrahydrofuran, and 9.0 g (60%, 225 mmol) of sodium hydride was added thereto. The mixture was stirred at room temperature for 30 minutes. 36.9 g (225 mmol) of ethyl phenylacetate was added thereto, the mixture was stirred for one hour, and then 200 ml of N,N-dimethylformamide was added thereto. The mixture was further stirred under slight heating for 4 hours. The solvent was removed under reduced pressure, and the residue was then treated with ethyl acetate and water. The resulting precipitate was filtered and washed with water and diethyl lether to give 20.3 g of the title compound in a yield of 48%.
1H NMR (DMSO-d6, ppm): xcex4 3.79 (2H, s), 7.28 (1H, t), 7.30-7.43 (4H, m), 7.60 (1H, d), 8.12 (1H, dd), 9.00 (1H, s); FAB MS(m/e)=283 [M+1].
1-3) Synthesis of t-Butyl 5-Nitro-3-[(2-phenylacetyl)amino]-1H-indazol-1-carboxylate
8.0 g (28 mmol) of the compound obtained in Preparation 1-2) was dissolved in 130 Ml of tetrahydrofuran, and 3.2 g (80 mmol) of sodium hydroxide in 20 ml of water and 7.1 g (33 mmol) of di-t-butylcarbonate were added thereto. The mixture was stirred for one hour. After removal of solvents under reduced pressure, the residue was subjected to recrystalization using ethyl acetate and hexane to give the title compound quantatively.
1H NMR(CDCl3, ppm): xcex4 1.69 (9H, s), 3.65 (2H, s), 7.24-7.30 (5H, m), 7.68 (1H, dd), 7.91 (1H, s), 8.00 (1H, d), 8.73 (1H, s).
1-4) Synthesis of t-Butyl 5-Amino-3-[(2-phenylacetyl)amino]-1H-indazol-1-carboxylate
11 g (28 mmol) of the compound obtained in Preparation 1-3) was dissolved in methanol, and palladium-adsorbed activated carbon (10%) was added thereto. The mixture was stirred under hydrogen atmosphere for 2 hours. The resulting suspension was filtered through celite, and then the filtrate was concentrated to give the title compound quantatively.
1H NMR (CDCl3, ppm): xcex4 1.68 (9H, s), 3.68 (2H, s), 7.25-7.31 (5H, m), 7.45 (1H, dd), 7.71 (1H, s), 7.94 (1H, d), 8.64 (1H, s).
1-5) Synthesis of t-Butyl 5-[[(3-Chloropropyl)sulfonyl]amino]-3-[(2-phenylacetyl)amino]-1H-indazol-1-carboxylate
6.3 g (17 mmol) of the compound obtained in Preparation 1-4) was dissolved in 120 Ml of dichloromethane, and 13 ml(170 mmol) of pyridine and 27 ml (22 mmol) of 3-chloropropanesulfonyl chloride were added thereto. The mixture was stirred at room temperature for 2 hours. The solvent was removed under reduced pressure, and then the residue was purified by silica gel column chromatography(eluent:n-hexane/ethylacetate=1/1 (v/v)) to give the title compound quantatively.
1H NMR (CD3OD, ppm): xcex4 1.69 (9H, s), 2.20 (2H, m), 3.17 (2H, t), 3.65 (4H, m), 7.29 (5H, m), 7.30 (1H, m), 7.40 (1H, d), 7.60 (1H, s); ESI MS(m/e)=507 [M+1].
1-6) Synthesis of t-Butyl 5-(1,1-Dioxo-1xcex6-isothiazolidin-2-yl)-3-[(2-phenylacetyl)amino]-1H-indazol-1-carboxylate
8.6 g (17 mmol) of the compound obtained in Preparation 1-5) was dissolved in 150 Ml of N,N-dimethylformamide, and 1.43 g(34 mmol) of sodium hydride was added thereto. The mixture was stirred for 30 minutes. The solvent was removed under reduced pressure. The residue was extracted with ethyl acetate, and then the extracted ethyl acetate solution was washed with water three times. The solvent was under reduced pressure, and then the residue was purified by silica gel column chromatography(eluent:n-hexane/ethylacetate=1/2(v/v)) to give 8.0 g of the title compound quantatively.
1H NMR (CDCl3, ppm): xcex4 1.70 (9H, s), 2.50 (2H, m), 3.28 (2H, t), 3.80 (4H, m), 7.30 (5H, m), 7.68 (1H, m), 7.91 (1H, s), 8.00 (1H, d), 8.73 (1H, s); ESI MS(m/e)=471 [M+1].